Investigators at the USDA and the Department of Defense have continued to share interest in the potential immunological activity of cockroach debris left in dwellings after treatment with various insecticides and cleaning agents. The freeze-dried extracts of Cockroach debris and a pool of rabbit antiserum, prepared by LST with source material provided by ARS, are now the references of an ELISA system. This year, exposure-timed samples were assayed by ELISA; results were directly correlated to length of exposure. Two mock kitchens at ARS were surveyed by swabbing measured areas; the swabs were extracted, assayed and related to the timed exposure samples by ELISA. The kitchen areas have been cleaned using several methods, and the swabbing/ELISA process has been repeated to verify that the antigen has been removed. Plans have been drafted to release a known quantity of Cockroaches into the kitchen areas and repeat the studies. We have been approached to share the system with Allergy/Asthma researchers at Johns Hopkins in Baltimore.